Dual clutches having two friction clutches situated in one housing are known, for example, from German Patent Application No. 10 2008 019 949 A1. Here, the friction clutches are each actuated by a hydrostatic actuator, which exerts a pressure on an actuating element in the form of a lever spring, which in turn tensions a pressing plate against the pressure plate directly or by means of a tie rod, depending on the arrangement of the friction clutch, while interposing friction linings of a clutch plate. A directly actuated dual clutch is known from European Patent No. 1 524 446 B1, where the pressing plates are actuated by actuating elements, which are situated directly between the hydrostatic actuator and the pressing plates without interposing a lever spring.
Depending on the pressure applied to the actuating element by the hydrostatic actuator, the actuating element moves along an actuation path and sets a corresponding moment of friction depending on its position along the actuation path. Because of the elasticities of the materials of the dual clutch, which are present in practice, actuation of the one friction clutch influences the position of the disengaging element of the other friction clutch, so that when pressure is present a modified torque is transmitted via the disrupted friction clutch, which can result in a reinforcement or weakening of the torque desired by prescribing the pressure, depending on the arrangements of the friction clutches in the dual clutch.
A method for modeling of and compensation for such over-addressing processes is known from International Patent Application No. 2004/036078 A1. In this case, the characteristic curves of the friction clutches, from which the torque transmissible via the friction clutches is derived, depending on the position along the actuation travel path, are cited. These characteristic curves contain, among other things, the coefficient of friction of the friction clutch, as a proportionality value. A nominal clutch torque corrected for the coefficient of friction is therefore obtained, and from it is obtained the shift of the characteristic curve in the event of crosstalk when the other friction clutch is actuated. This method is complex and comparatively imprecise, due, for example, to changing coefficients of friction of the friction clutches between two adaptation processes of the coefficient of friction.